Why Researchers Are Figuring Out How to Hack Climate Change with Solar Shading

Starting with the Industrial Revolution (or perhaps even earlier), humanity began an unintentional manipulation of the climate of planet Earth, turning up a thermostat we didn’t realize was within our reach. The carbon dioxide pumped into the atmosphere by burning fossil fuels has raised global temperatures, resulting in a host of harmful impacts.

The obvious solution is to stop turning up the heat by eliminating our greenhouse gas emissions. Though that is easier said than done.

But what if we could also take steps to intentionally turn the thermostat down? This is the realm of geoengineering—efforts to intelligently manage the earth’s complex climate system.

There are a number of ways that this could be done, but the one that seems to generate the strongest reactions is the prospect of shading the planet. Since greenhouse gases work by holding in heat energy leaving the planet, you can counteract them by reducing the amount of solar energy coming in.

Such an action would take inspiration not from science fiction (launching giant mirrors into orbit, perhaps), but from volcanoes. Large eruptions can have a cooling effect for several years, because volcanic sulfur dioxide gas forms microscopic particles high in the atmosphere that reflect some sunlight back into space before it can warm the earth’s surface.